1. Field of the Invention
This invention relates generally to a technique for casting a product in which a cast product is integral with a hollow member. In the technique, the hollow member is previously positioned in a casting mold and casting operation is thereafter performed such that the product in which the cast product is integral with the hollow member is cast. More particularly, the invention relates to a technique for casting a product wherein a cast product has a hollow interior with which a hollow member communicates. Casting a product in which a cast product is integral with a hollow member previously positioned in a casting mold will hereinafter be referred to as "integrally attaching the hollow member to the cast product by casting" in the description. The invention relates to a method of integrally attaching a hollow member to a cast product by casting and an apparatus therefor.
2. Description of the Prior Art
Japanese patent publication No. 62-21454 (1987) discloses a conventional method of integrally attaching a hollow member to a cast product. In the disclosed method, both ends of the hollow member is fixed by a casting mold so that the hollow member is positioned with respect to the casting mold and so that a molten metal is prevented from penetrating the hollow member. The casting operation is performed in this condition. Japanese patent publication No. 57-56147 (1982) discloses another method in which a core is provided in the hollow member so that the latter is prevented from collapse during the casting operation A cast product with a hollow interior is thus produced by each of the above-described conventional techniques. FIG. 18 illustrates a product W in which a cast product c is integral with a hollow member h. The product W is provided with a hollow interior ws.
However, a method has not been developed of integrally attaching a hollow member 2 to the cast product c so that the hollow member 2 communicates with the hollow interior ws of the cast product C as shown in FIG. 17. In the status of the prior art, accordingly, the cast product c is first cast and the hollow member 2 is thereafter fixed to the cast product c.